Even after a second dose, COVID-19 vaccines may not provide protection for transplant recipients

In one study, nearly half of participants produced no antibodies.

Jessica Rinaldi/Globe Staff/File 2021

A recent research study brought some troubling news to people with organ transplants. It reported that the first dose of COVID-19 vaccines induced antibodies in barely one-sixth of transplant recipients, who must take drugs to suppress their immune systems.

But patients and doctors held out hope that the second dose would do the trick.

Last week, a follow-up research report from the same Johns Hopkins team threw some chilly — if not ice cold — water on that hope. A second dose appeared to be no help for nearly half the participants.

“Things are better but not great,” said Dr. Dorry Segev, an author of the study, published in JAMA. “The second dose is helpful, but it’s not a guarantee of immunity.”

After the first and second doses of the Moderna or Pfizer vaccines, 46 percent of study participants produced no detectable antibodies against the coronavirus. And those who did respond produced fewer antibodies than people with strong immune systems.

The Johns Hopkins team did not study the effects of the Johnson & Johnson vaccine. But Segev said he was not optimistic that other types of vaccines would perform differently, because the fundamental problem is that transplant recipients need to tamp down their immune systems to prevent their bodies from rejecting the organ. And in response to any vaccine, a suppressed immune system doesn’t kick into gear as readily as a robust one.

“This news is an emotional letdown for sure,” said John A. Nucci, who received a living-donor kidney from a family friend in 2018. “Like everyone else, I was hoping that it would be over soon for us. It looks like we’re going to have to wait a little longer.”

Although vaccinated, the 69-year-old Nucci, who is Suffolk University’s senior vice president for external affairs, is working remotely, avoiding crowds, and always masking and distancing. “I haven’t gone to a restaurant in over a year,” he said.

His predicament, he said, is further motivation for everyone to get vaccinated. “This is not just about how you feel about getting a vaccine. This is about how you can affect other people.”

Nucci added in an e-mail, “I am fortunate in that I have been able to work remotely, but there are many transplant recipients who don’t have that option and they will unfortunately still be at risk every time they go to work.”

The Johns Hopkins findings are “similar to what we’re seeing across multiple different studies in organ transplant recipients,” said Dr. Camille Nelson Kotton, clinical director for Transplant and Immunocompromised Host Infectious Diseases at Massachusetts General Hospital. “We suspect [transplant recipients] are less well protected.”

Even people who do produce antibodies can’t be confident that they’re protected. It’s not known what level of antibodies is needed. And antibodies are only one part of the immune system.

The Johns Hopkins study did not measure T cells, another important immune fighter. And many transplant recipients take “medications that purposefully block T-cell response,” said Segev, who is director of the Epidemiology Research Group in Organ Transplantation at the Johns Hopkins University School of Medicine. “Don’t assume you have immunity even if your antibody response looks good.”

Still, the second dose clearly made a difference for some. In the Johns Hopkins study, 39 percent had no response after the first dose — and then did respond to the second shot.

That raises hope for what a third shot might do, if it were authorized. Researchers in France and Israel are studying the question, and Segev’s team is seeking federal approval to do the same.

Meanwhile, even though it’s technically not allowed, some transplant patients in the United States have managed to get third doses, Segev said.

For now, doctors offer this advice for their transplant patients.

First, get vaccinated.

“It gets your immune system started,” Segev said. Any protection is better than none, and even if the vaccine doesn’t prevent infection, it may make the illness less severe if you catch it.

Second, even while vaccinated, behave exactly as you would if you were not vaccinated. “The most that a transplant patient should be doing is what the CDC tells you is safe for unvaccinated people to do,” Segev said.

Third, make sure that people you regularly come in contact with are vaccinated. That will help protect you.

And finally: Don’t despair.

“We hope in the near future we will figure out some kind of better vaccination protection for [transplant patients],” Kotton said. “It could be more doses, double doses. It could be [that] a combination of different vaccines may end up being more protective.”

She tells her patients: “Hold tight. Hopefully we will have more information within the next few months.”